1. Field of the Invention
The present invention relates to a filter and, more particularly, to a filter for separating substances with different melting points.
2. Description of the Related Art
Conventionally, for reclamation and recycling of zinc, discarded materials of zinc with impurities that have melting points higher than that of zinc are melted in a heated crucible to separate liquid zinc and solid impurities. Moreover, said discarded materials have to be heated to a temperature higher than the melting point of zinc but lower than those of the impurities in order to obtain the liquid zinc and solid impurities. However, workers for stirring the melted materials to speed up the melting rate and for scooping the solid impurities out are required, and who will easily inhale a mass of pernicious gas produced while the discarded materials are melted. Besides, what are scooped out may not only be the solid impurities but also some liquid zinc attaching on the solid impurities, and this will greatly lower the recycling efficiency of zinc.
A Taiwan utility patent with Publication No. 176994 discloses a continuous-vibrating filter for reclamation and recycling of zinc. The continuous-vibrating filter comprises a furnace and a filtering plate passing through the furnace and providing a plurality of through holes, with the filtering plate being inclined and connecting to a vibrator at a higher end thereof. When the continuous-vibrating filter is used to reclamation, the furnace also provides a temperature higher than the melting point of zinc but lower than those of the impurities and the discarded materials are placed at the higher end in advance. And then the discarded materials slowly slide to a lower end of the filtering plate with the vibrator being actuated to shake the filtering plate while the discarded materials slide along the filtering plate and pass through the furnace, zinc within said discarded materials will then be melted and goes through the through holes of the filtering plate to be collected in a container. In the meanwhile, solid impurities in said discarded materials are finally piled up at the lower end of the filtering plate.
Nevertheless, there are still some disadvantages of the continuous-vibrating filter. First, the liquid zinc flows through the through holes of the filtering plate owing to weight itself, which is thus collected slowly. Second, because of the way by which the liquid zinc is collected, there is still a great amount of zinc attached to the solid impurities or the filtering plate, and output of zinc will thus be low still. Accordingly, there is a need for redesigning the conventional filter.